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arXiv · 1909.03988

Asymmetric butterfly velocities in 2-local Hamiltonians

Yong-Liang Zhang·Vedika Khemani
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Abstract

The speed of information propagation is finite in quantum systems with local interactions. In many such systems, local operators spread ballistically in time and can be characterized by a "butterfly velocity", which can be measured via out-of-time-ordered correlation functions. In general, the butterfly velocity can depend asymmetrically on the direction of information propagation. In this work, we construct a family of simple 2-local Hamiltonians for understanding the asymmetric hydrodynamics of operator spreading. Our models live on a one dimensional lattice and exhibit asymmetric butterfly velocities between the left and right spatial directions. This asymmetry is transparently understood in a free (non-interacting) limit of our model Hamiltonians, where the butterfly speed can be understood in terms of quasiparticle velocities.

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BibTeXRIS

Yong-Liang Zhang, Vedika Khemani. 2019-09-09. Asymmetric butterfly velocities in 2-local Hamiltonians. https://doi.org/10.21468/scipostphys.9.2.024

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